1. Field of the Invention
The invention is related to therapeutic compounds which are CB1 receptor ligands, pharmaceutical compositions containing these compounds, manufacturing processes thereof and uses thereof, and more particularly to compounds that are CB1 receptor agonists. More particularly, the present invention is related to compounds that may be effective in treating pain, cancer, multiple sclerosis, Parkinson's disease, Huntington's chorea, Alzheimer's disease, anxiety disorders, gastrointestinal disorders and cardiovascular disorders.
2. Discussion of Relevant Technology
Pain management has been an important field of study for many years. It has been well known that cannabinoid receptor (e.g., CB1 receptor, CB2 receptor) ligands including agonists, antagonists and inverse agonists produce relief of pain in a variety of animal models by interacting with CB1 and/or CB2 receptors. Generally, CB1 receptors are located predominately in the central nervous system, whereas CB2 receptors are located primarily in the periphery and are primarily restricted to the cells and tissues derived from the immune system.
While CB1 receptor agonists, such as Δ9-tetrahydrocannabinol (Δ9-THC) and anadamide, are useful in anti-nociception models in animals, they tend to exert undesired CNS side-effects, e.g., psychoactive side effects, the abuse potential, drug dependence and tolerance, etc. These undesired side effects are known to be mediated by the CB1 receptors located in CNS. There are lines of evidence, however, suggesting that CB1 agonists acting at peripheral sites or with limited CNS exposure can manage pain in humans or animals with much improved overall in vivo profile.
Therefore, there is a need for new CB1 receptor ligands such as agonists, antagonists or inverse agonists that are useful in managing pain or treating other related symptoms or diseases with reduced or minimal undesirable CNS side-effects.